1. Field of Invention
The present invention relates to a safety device for vehicle, and more particular to a drunk driving prevention system and method, which detects the eye activity of the driver in the sense of determining the presence of alcohol for indicating whether the driver is capable of driving the vehicle safely.
2. Description of Related Arts
Driving under the influence (DUI), commonly called “drunk driving” refers to operating a vehicle while one's blood alcohol content is above the legal limit set by state. Every year, ten thousands of people were killed and more than hundred thousands of people were injured due to drunk driving. Every single injury and death caused by drunk driving is totally preventable. Recently, anti-drunk driving apparatuses to eliminate drunk driving are provided.
For example, an alcohol sensor is considered as one of the popular anti-drunk driving apparatuses to be installed into the vehicle, wherein when the driver is guided to blow a breath to the alcohol sensor, the alcohol sensor will measure the alcohol concentration. If the alcohol concentration measured by the alcohol sensor is higher than a predetermined threshold, an ignition interlock is activated to stop the ignition of the vehicle. In other words, the alcohol sensor can be deactivated only when the alcohol concentration measured is below the predetermined threshold to start the vehicle. However, such alcohol sensor has a drawback that even though the driver under the influence can start and drive the vehicle by having other person to blow a breath to the alcohol sensor instead of the driver in order to deactivate the alcohol sensor.
The alcohol sensor is not accurate and will falsely determine the alcohol concentration of the driver by blown breath. For example, after the driver rinses his or her mouth in the morning by a mouth rinse which contains alcohol as one of the ingredients, the alcohol concentration measured by the alcohol sensor will be higher than the predetermined threshold.
Furthermore, the drunk driver can cheat the alcohol sensor by any filter at the mouthpiece of the alcohol sensor when blowing the breath thereto. Therefore, the measured alcohol concentration by the alcohol sensor is lower than the actuate alcohol concentration of the driver because of the filter.
The alcohol sensor can only stop the ignition of the vehicle. Once the vehicle is start, the drunk driver is able to drive the vehicle. In other words, there is no prevention to stop the drunk driver while driving.